Conventional package-type power modules need gel encapsulation of semiconductor elements. A large number of assembly process steps and high parts cost are required for such power modules. Transfer-molded power modules having semiconductor elements therein are therefore being developed (see, for example, Patent Literature 1). A device having a resin-molded semiconductor package in which a circuit board including a drive circuit for driving a semiconductor element is fixed with screws or the like has been proposed (see, for example, Patent Literature 2).
However, in the case where screws or the like are used, there is a problem in that the number of component parts is increased, which leads to an increased overall weight. There is also a problem in that the device is increased in size by an amount corresponding to the circuit board. Further, in the case of a semiconductor device for use in a motor vehicle, the ambient temperature is high and a semiconductor element such as a SIC heats itself to a high temperature. Therefore, there is a need to use high-temperature-resistant parts, resulting in an increase in manufacturing cost.
For this reason, a semiconductor device has been proposed in which a power semiconductor element and a control semiconductor element for controlling the power semiconductor element are mounted on one cooling body and are encapsulated in resin (see, for example, Patent Literature 3). With this arrangement, a reduction in the number of component parts and a reduction in weight can be achieved, the need for a circuit board such as a printed circuit board can be eliminated, and the control semiconductor element can be cooled.